ACTA2 and Hepatic fibrosis: Indeed, nizatidine significantly reduced liver fibrosis measured by collagen proportionate area (CPA), α smooth muscle actin (αSMA) staining, quantitative analysis of hydroxyproline, and expression of genes mediating fibrogenesis (Acta2, Col1a1, Tgfb-1, and Timp1; Fig. 4e, f).